Where's the guy who was bashing IB for "bad security implementation" and wanted to goto Ameritrade???
I have not had any such problems with ameritrade. My experience is some cheap ISP is the most likely one to sell out their clients profile and e-mail addresses.
Or worse, the guy had spyware on his computer that transmitted his keyboard input to some remote IP operated by professional intruders that collect online banking data, email addresses etc.
I have had that happen with my Ameritrade email address, although I will admit that I used "Ameritrade@(my domain)" so its possible that its just someone sending emails to Ameritrade at every domain. However I also have gotten spams to a second Ameritrade account which is registered with the email address of "Ameritrade2@(my domain)" which seems unlikely to have been randomly guessed by spammers. My ISP is Verizon BTW
My Ameritrade email addresses have not been compromised like that--but I do take security measures from the computer I log on from. By the way, can you just short those stocks if any broker lets you short them?